* ul* Raindrops and control panels are separate,Â convenience of the line out. Large raindrops board, more conducive detected rain. Board with positioning holes to facilitate installation Working Voltage: 3.3Volt / 5Volt DC Power indicator, the output signal LED indicator. TTL-level output, TTL output valid signal is low. Driving capability around 100mA. Output signal can directly connect to microcontroller, relays, buzzer, small fan, and etc. Sensitivity adjustment by trimpot. LED lights up when there is no rain output is high, and when rain drops up, output isÂ low, LED lights off. Control panel size : 3 * 1.6 MM Rain drop detection module size : 5.4 * 4.0 MM * /ul* How this item working? Digital OutputWhen connected to a 5V supply power lights, no water droplets on-board sensors, DO/ data output is high, switch lights ON, and where drop of water, DO/ data output is low, the light indicator ON. Brush above water droplets, has returned to output high state. Analog OutputAO/ analog output, you can connect the microcontroller to detect/ make calculation from AD and calculate of rain drop size. DO TTL OutputDO TTL digital outputs can also be connected to the microcontroller to detect whether there is rain.